Breadboard Help

Thread Starter

Rangineer

Joined Sep 16, 2020
4
Hi,
I am stuck on a problem. I'm basically back as a beginner - years and years ago I thought I got this stuff... Apparently not, so I need an expert.

I've got a battery pack connected to a breadboard. I've cut the tops of safety to act as wires (desperate times ya know). They work on the voltmeter.
Through the breadboard they are connected by:
Battery pack -> safety pins -> resister -> LED -> to safety pin -> Battery pack.

I have two LED's in parallel two check if the diode direction makes a difference. Then I have the whole circuit again in parallel but changed the resistor to be after the LED's rather than before, to see if that makes a difference.

I just want one of the LED's to light up. I have slotted all the components into the right slots and the batteries have been changed with ones that I know work. Also all the components, including the battery pack and the breadboard are new. So I am puzzled as to why the LED won't light up.

The voltage just from the battery pack is 8V. The resistor is 1kΩ.
I don't know what to do or search for. Please help. Thank you in advance.
 

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SamR

Joined Mar 19, 2019
2,778
Take your multimeter, and a bit of time, and understand what is going on under the surface of the breadboard. Your circuit on the breadboard is NOT connected correctly. The 4 long power rails on the top and bottom and the 1-23 columns are connected on a different axis from each other. the power rails run horizontal and the 1-23 columns are vertical. Once you understand the breadboard connectivity building and connecting circuits will become easier.
 

Thread Starter

Rangineer

Joined Sep 16, 2020
4
Thank you very much.
It was easy for you to see but for me I didn't get it - been years since I worked with one of these. The back also has adhesive so didn't see the connector lines. Thank you, I'm very grateful for the help.
Up and running wooooo!!!
 

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Alec_t

Joined Sep 17, 2013
11,739
I have two LED's in parallel two check if the diode direction makes a difference.
If the two LEDs are in anti-parallel (anode of one connected to cathode of the other) that's fine, because each diode protects the other from having an excessive reverse voltage across it. LEDs will die if the reverse voltage (reckon on about 5V, but it varies between diode types) is excessive.
 

dl324

Joined Mar 30, 2015
11,866
Up and running wooooo!!!
The leads on LEDs don't like to be stressed. Use some needlenose pliers to form the leads like this:
clipimage.jpg

You can also use pliers to form the leads on the resistors (making sure you don't apply much pressure where the lead exits the body).
clipimage.jpg

Or you can use one of these:
clipimage.jpg
 
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